| // SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) |
| // Copyright (C) 2018 Facebook |
| // Author: Yonghong Song <yhs@fb.com> |
| |
| #define _GNU_SOURCE |
| #include <ctype.h> |
| #include <errno.h> |
| #include <fcntl.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <sys/stat.h> |
| #include <sys/types.h> |
| #include <unistd.h> |
| #include <dirent.h> |
| |
| #include <bpf/bpf.h> |
| |
| #include "main.h" |
| |
| /* 0: undecided, 1: supported, 2: not supported */ |
| static int perf_query_supported; |
| static bool has_perf_query_support(void) |
| { |
| __u64 probe_offset, probe_addr; |
| __u32 len, prog_id, fd_type; |
| char buf[256]; |
| int fd; |
| |
| if (perf_query_supported) |
| goto out; |
| |
| fd = open("/", O_RDONLY); |
| if (fd < 0) { |
| p_err("perf_query_support: cannot open directory \"/\" (%s)", |
| strerror(errno)); |
| goto out; |
| } |
| |
| /* the following query will fail as no bpf attachment, |
| * the expected errno is ENOTSUPP |
| */ |
| errno = 0; |
| len = sizeof(buf); |
| bpf_task_fd_query(getpid(), fd, 0, buf, &len, &prog_id, |
| &fd_type, &probe_offset, &probe_addr); |
| |
| if (errno == 524 /* ENOTSUPP */) { |
| perf_query_supported = 1; |
| goto close_fd; |
| } |
| |
| perf_query_supported = 2; |
| p_err("perf_query_support: %s", strerror(errno)); |
| fprintf(stderr, |
| "HINT: non root or kernel doesn't support TASK_FD_QUERY\n"); |
| |
| close_fd: |
| close(fd); |
| out: |
| return perf_query_supported == 1; |
| } |
| |
| static void print_perf_json(int pid, int fd, __u32 prog_id, __u32 fd_type, |
| char *buf, __u64 probe_offset, __u64 probe_addr) |
| { |
| jsonw_start_object(json_wtr); |
| jsonw_int_field(json_wtr, "pid", pid); |
| jsonw_int_field(json_wtr, "fd", fd); |
| jsonw_uint_field(json_wtr, "prog_id", prog_id); |
| switch (fd_type) { |
| case BPF_FD_TYPE_RAW_TRACEPOINT: |
| jsonw_string_field(json_wtr, "fd_type", "raw_tracepoint"); |
| jsonw_string_field(json_wtr, "tracepoint", buf); |
| break; |
| case BPF_FD_TYPE_TRACEPOINT: |
| jsonw_string_field(json_wtr, "fd_type", "tracepoint"); |
| jsonw_string_field(json_wtr, "tracepoint", buf); |
| break; |
| case BPF_FD_TYPE_KPROBE: |
| jsonw_string_field(json_wtr, "fd_type", "kprobe"); |
| if (buf[0] != '\0') { |
| jsonw_string_field(json_wtr, "func", buf); |
| jsonw_lluint_field(json_wtr, "offset", probe_offset); |
| } else { |
| jsonw_lluint_field(json_wtr, "addr", probe_addr); |
| } |
| break; |
| case BPF_FD_TYPE_KRETPROBE: |
| jsonw_string_field(json_wtr, "fd_type", "kretprobe"); |
| if (buf[0] != '\0') { |
| jsonw_string_field(json_wtr, "func", buf); |
| jsonw_lluint_field(json_wtr, "offset", probe_offset); |
| } else { |
| jsonw_lluint_field(json_wtr, "addr", probe_addr); |
| } |
| break; |
| case BPF_FD_TYPE_UPROBE: |
| jsonw_string_field(json_wtr, "fd_type", "uprobe"); |
| jsonw_string_field(json_wtr, "filename", buf); |
| jsonw_lluint_field(json_wtr, "offset", probe_offset); |
| break; |
| case BPF_FD_TYPE_URETPROBE: |
| jsonw_string_field(json_wtr, "fd_type", "uretprobe"); |
| jsonw_string_field(json_wtr, "filename", buf); |
| jsonw_lluint_field(json_wtr, "offset", probe_offset); |
| break; |
| default: |
| break; |
| } |
| jsonw_end_object(json_wtr); |
| } |
| |
| static void print_perf_plain(int pid, int fd, __u32 prog_id, __u32 fd_type, |
| char *buf, __u64 probe_offset, __u64 probe_addr) |
| { |
| printf("pid %d fd %d: prog_id %u ", pid, fd, prog_id); |
| switch (fd_type) { |
| case BPF_FD_TYPE_RAW_TRACEPOINT: |
| printf("raw_tracepoint %s\n", buf); |
| break; |
| case BPF_FD_TYPE_TRACEPOINT: |
| printf("tracepoint %s\n", buf); |
| break; |
| case BPF_FD_TYPE_KPROBE: |
| if (buf[0] != '\0') |
| printf("kprobe func %s offset %llu\n", buf, |
| probe_offset); |
| else |
| printf("kprobe addr %llu\n", probe_addr); |
| break; |
| case BPF_FD_TYPE_KRETPROBE: |
| if (buf[0] != '\0') |
| printf("kretprobe func %s offset %llu\n", buf, |
| probe_offset); |
| else |
| printf("kretprobe addr %llu\n", probe_addr); |
| break; |
| case BPF_FD_TYPE_UPROBE: |
| printf("uprobe filename %s offset %llu\n", buf, probe_offset); |
| break; |
| case BPF_FD_TYPE_URETPROBE: |
| printf("uretprobe filename %s offset %llu\n", buf, |
| probe_offset); |
| break; |
| default: |
| break; |
| } |
| } |
| |
| static int show_proc(void) |
| { |
| struct dirent *proc_de, *pid_fd_de; |
| __u64 probe_offset, probe_addr; |
| __u32 len, prog_id, fd_type; |
| DIR *proc, *pid_fd; |
| int err, pid, fd; |
| const char *pch; |
| char buf[4096]; |
| |
| proc = opendir("/proc"); |
| if (!proc) |
| return -1; |
| |
| while ((proc_de = readdir(proc))) { |
| pid = 0; |
| pch = proc_de->d_name; |
| |
| /* pid should be all numbers */ |
| while (isdigit(*pch)) { |
| pid = pid * 10 + *pch - '0'; |
| pch++; |
| } |
| if (*pch != '\0') |
| continue; |
| |
| err = snprintf(buf, sizeof(buf), "/proc/%s/fd", proc_de->d_name); |
| if (err < 0 || err >= (int)sizeof(buf)) |
| continue; |
| |
| pid_fd = opendir(buf); |
| if (!pid_fd) |
| continue; |
| |
| while ((pid_fd_de = readdir(pid_fd))) { |
| fd = 0; |
| pch = pid_fd_de->d_name; |
| |
| /* fd should be all numbers */ |
| while (isdigit(*pch)) { |
| fd = fd * 10 + *pch - '0'; |
| pch++; |
| } |
| if (*pch != '\0') |
| continue; |
| |
| /* query (pid, fd) for potential perf events */ |
| len = sizeof(buf); |
| err = bpf_task_fd_query(pid, fd, 0, buf, &len, |
| &prog_id, &fd_type, |
| &probe_offset, &probe_addr); |
| if (err < 0) |
| continue; |
| |
| if (json_output) |
| print_perf_json(pid, fd, prog_id, fd_type, buf, |
| probe_offset, probe_addr); |
| else |
| print_perf_plain(pid, fd, prog_id, fd_type, buf, |
| probe_offset, probe_addr); |
| } |
| closedir(pid_fd); |
| } |
| closedir(proc); |
| return 0; |
| } |
| |
| static int do_show(int argc, char **argv) |
| { |
| int err; |
| |
| if (!has_perf_query_support()) |
| return -1; |
| |
| if (json_output) |
| jsonw_start_array(json_wtr); |
| err = show_proc(); |
| if (json_output) |
| jsonw_end_array(json_wtr); |
| |
| return err; |
| } |
| |
| static int do_help(int argc, char **argv) |
| { |
| fprintf(stderr, |
| "Usage: %1$s %2$s { show | list }\n" |
| " %1$s %2$s help }\n" |
| "\n" |
| " " HELP_SPEC_OPTIONS " }\n" |
| "", |
| bin_name, argv[-2]); |
| |
| return 0; |
| } |
| |
| static const struct cmd cmds[] = { |
| { "show", do_show }, |
| { "list", do_show }, |
| { "help", do_help }, |
| { 0 } |
| }; |
| |
| int do_perf(int argc, char **argv) |
| { |
| return cmd_select(cmds, argc, argv, do_help); |
| } |